Hi Marsha, Two things are very important
1 Water, a constant supply is needed especially in summer
2 short grass, if your grass is long cut it, otherwise you will have sheep with dirty back ends and that leads to more work
and the number of your local fallen stock scheme - sheep have a knack of waking up dead!!
without more information on what you plan to do with them its difficult to advise. so many ways to rear sheep... so little time